Latitudinal Variation in the Geometric Morphology of the Largemouth Bass, Micropterus salmoides

Geometric morphology can be influenced by a number of biotic and abiotic factors, including predator-prey interactions and habitat structure. We measured the external morphology of Micropterus salmoides (largemouth bass, LMB) from two stateslatitudes in northeastern United Sstates to assess the potential divergence of body shape. LMB varied in overall body shape (CVA, P<0.001) between states, with Maine populations exhibiting shorter jaws (ANOVA, P<0.001), and thicker caudal peduncle depths (ANOVA, P<0.001) compared to LMB in Pennsylvania. We propose these observed differences in morphological traits suggest jaw length may be influenced by prey availability and resource utilization, while peduncle depth is better explained by surrounding habitat structure. These findings show that body shape is relatively variable and is influenced by a complex array of environmental factors, even at over relatively small latitudinal gradients differences.